The 3.7% decrease in October was revised from a 3.8% contraction ATA reported on Nov. 20. As a result, the SA index equaled 118.0 (2000=100) in November versus 113.8 in October.

Compared with November 2011, the SA index was up 1%, after contracting 2.1% on a year-over-year basis in October. Year-to-date, compared with the same period last year, tonnage was up 2.8%.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 115.7 in November, which was 6.5% below the previous month.

"Sandy impacted both October's and November's tonnage readings," ATA Chief Economist Bob Costello said. "But it was still good to see tonnage snap back in November."

Costello expects a boost to flatbed tonnage from the rebuilding in the areas impacted by Sandy, but most of that won't happen until the spring when the money starts flowing and the weather is conducive to building.

"Outside of Sandy, if the fiscal cliff isn't fixed in time, expect a slowdown in tonnage early next year as paychecks shrink for all households," Costello said. "Since trucks account for the vast majority of deliveries in the retail supply, any reduction in consumer spending will hurt."

Costello added that even if we don't go off the fiscal cliff, he expects slower tonnage growth in 2013 than 2012, as better housing starts and auto sales will be offset by slower factory output and consumer spending.